Centrifugal spray device



Oct. 30, 1962 CENTRIFUGAL SPRAY DEVICE C. L. FICKER Filed Jan. 17, 1961 INVENTOR CHARLES L. F/CKER Br Maw W A Ilarney United States Patent 3,061,200 CENTRIFUGAL SPRAY DEVICE Charles L. Ficker, Cos Cob, Conn., assignor to United States Steel Corporation, 'a corporation of New Jersey Filed Jan. 17, 1961, Ser. No. 83,318 3 Claims. (Cl. 239-222) This invention relates to an improved centrifugal spray device.

Although my invention is not thus limited, my spray device is particularly useful for applying a liquid coating composition to an internal cylindrical surface, for example painting the inside of a steel drum. One problem encountered with conventional centrifugal spray devices is that they produce spray patterns of narrow axial dimension. Consequently they do not readily achieve a uniform coating, but more often produce a spiral effect as they are moved axially along an internal surface.

An object of the present invention is ,to provide an improved centrifugal spray device which produces a broad spray pattern.

A more specific object is to provide an improved centrifugal spray device which includes nozzles for injecting a coating liquid, and a spray head for receiving liquid from the nozzles and having a labyrinth passage for dispersing the liquid into fine particles and diverging discharge passages for distributing the particles in a broad pattern in the axial direction.

In accomplishing these and other objects of the invention, I have provided improved details of structure, a preferred form of which is shown in the accompanying drawing, in which:

FIGURE 1 is a vertical sectional view of a spray device constructed in accordance with my invention; and

FIGURE 2 is a section on line lI- II of FIGURE 1.

My spray device includes a stationary tubular supporting member 10, a rotatable shaft 12 within said supporting member, and a bearing 13 in which said shaft is journaled. Collars 14 and 15 are fixed to the inside of the supporting member 10 and to the outside of shaft 12 respectively for retaining the shaft and hearing. The shaft is connected to any suitable drive mechanism (not shown) for rotating it at high speed. A stationary annular housing 16 is fixed to the end of the supporting member 10. The housing has an inlet 17 connected to a suitable source of coating liquid or the like, not shown. This inlet leads to an annular chamber 18 in the back of the housing. The front of the housing has a counterbore 19 in which I mount a plurality of converging nozzles 20- uniformly spaced around the circumference. The housing has pas-.

sages 21 which afford communication between chamber 18 and the inlet ends of the nozzles.

Shaft 12 extends beyond the housing 16 and on its end carries a hollow spray head formed essentially of front and back plates 22 and 23, front and back annular rims 24 and 25, and inner and outer screens 26 and 27. The front plate 22 has an internal hub 28 fitted over the shaft and is fixed to the end of the shaft by a nut 29. The back plate 23 and the rims 24 and are rigidly fixed to the outer portion of the front plate, as with machine screws 30. The back plate has a central opening 31 which loosely receives the end portion of housing 16 to permit relative rotation. The confronting faces of plates 22 and 23 are spaced apart and carry a plurality of interfitting ridges 32 of circular outline. The space between ridges forms a labyrinth passage 33 which extends outwardly from the outlet ends of nozzles 20. The ridges are of triangular cross section and their inner faces are conical. The spray head of course rotates with the shaft. The resulting centrifugal force throws liquid injected from the nozzles outwardly through the labyrinth passage,

, 3,061,200 Patented Oct. 30, 1962 2. where it impinges against the successive conical faces. This action disperses the liquid into fine particles by the time it reaches the outer portion of the passage, and also distributes the particles uniformly around the circumference of the plates.

The outer portion of the front plate 22 has an integral flange or wall 34 which bears against the back plate 23 and thus spans the full width of the spray head. Plate 22 has openings and recesses to receive screws 30 and rims 24 and 25, as shown in detail in FIGURE 1. Flange 34- also has radial discharge passages 35, 35a, 35b and 35c in the form of tubular conduits each closed around its full circumference. These passages are spaced around the circumference of flange 34 and afford communication between the circumferential edge of the labyrinth passage 33 and a chamber 36 intermediate the two rims. The inlet ends of the radial passages lies on a common circle, but the passages are arranged in groups, and the passages of each group diverge at different angles from the axis of rotation, whereby their outlet ends are spread across the width of flange 34 in a pattern such as that shown in FIGURE 2. Thus centrifugal force throws the particles of coating liquid across the full width of chamber 36. From the chamber centrifugal force throws the particles through the full width of the inner and outer screens 26 and 27, which further assure that the particles remain uniformly dispersed until they reach a surface where they are applied.

From the foregoing description it is seen that my invention affords a centrifugal spray device of simple construction, but which assures that coating liquid or the like is applied uniformly to a surface. The nozzles and labyrinth passage assure that the liquid is dispersed into fine particles and uniformly distributed around the circumference. The diverging discharge passages assure that the particles are spread over a broad band in the axial direction.

While I have shown and described only a single embodiment of my invention, it is apparent that modifications may arise. Therefore, I do not wish to be limited to the disclosure set forth but only by the scope of the appended claims.

I claim:

1. A spray device comprising supporting means, a shaft journaled in said supporting means for rotation about an axis, a hollow spray head fixed to said shaft and including an annular Wall spanning the full Width of the spray head, a pair of spaced apart annular rims fixed to said Wall and an annular screen fixed between said rims, said wall, rims and screen defining a chamber which surrounds the circumference of the spray head and is of substantial width in a direction parallel with the axis of rotation, the interior of said spray head having a labyrinth passage extending outwardly from its central portion to said wall and a plurality of radial discharge passages in said wall, said radial passages being in the form of tubular conduits each closed around its full circumference, said radial passages providing the only communication between said labyrinth passage and said chamber and having inlet ends which lie in a common circle around the circumference of said labyrinth passage, said radial passages being arranged in groups spaced around the circumference of said wall, the radial passages of each group diverging at different angles from the axis of rotation and thus reaching said chamber at locations spaced across a substantial portion of the width thereof, nozzles mounted on said support means and extending into the central portion of said spray head, and means for introducing liquid to said nozzles, said nozzles being adapted to inject liquid into said spray head, thus enabling centrifugal force resulting from rotation of said spray head to throw the liquid through said labyrinth passage, which disperses the liquid into fine particles uniformly distributed circumferentially, and thence through said radial passage, which distribute the particles across the width of said chamber, said screen providing openings in the outer circumference of said chamber across the width thereof to discharge the particles tangentially in a broad pattern in the axial direction.

2. A spray device comprising tubular supporting means, a shaft journaled within said supporting means for rotation about an axis, a hollow spray head fixed to said shaft and including an annular wall spanning the full width of the spray head, a pair of spaced apart annular rims fixed to said wall and an annular screen fixed between said rims, said wall, rims and screen defining a chamber which surrounds the circumference of the spray head and is of substantial width in a direction parallel with the axis of rotation, spaced apart interfitting ridges of circular outline and triangular cross section and having inwardly directed conical faces on opposite sides of the interior of the spray head, the space between said ridges forming a labyrinth passage extending outwardly from the central portion of the spray head to said wall, said wall having a plurality of radial discharge passages in the form of tubular conduits each closed around its full circumference, said radial passages providing the only communication between said labyrinth passage and said chamber and having inlet ends which lie in a common circle around the circumference of said labyrinth passage, said radial passages being arranged in groups spaced around the circumference of said wall, the radial passages of each group diverging at different angles from the axis of rotation and thus reaching said chamber at locations spaced across a substantial portion of the width thereof, an annular housing fixed to said supporting means and having an inlet for liquid and an annular passage extending therearound and communicating with said inlet, and a plurality of nozzles fixed to said housing and communicating with said annular passage and extending into the central portion of said spray head for injecting liquid, thus enabling centrifugal force resulting from rotation of said spray head to throw the liquid through said labyrinth passage, which disperses the liquid into fine particles uniformly distributed circumferentially, and thence through said radial passages, which distribute the particles across the width of said chamber, said screen providing openings in the outer circumference of said chamber across the width thereof to discharge the particles tangentially in a broad pattern in the axial direction.

3. A spray device comprising supporting means for rotation about an axis, a hollowspray head mounted on said supporting means, the interior of said spray head having a labyrinth passage extending outwardly from its central portion, an annular wall surrounding the circumference of said passage and spanning the full width of the spray head, and an annular chamber surrounding the outer circumference of said wall, said chamber being of substantial width in a direction parallel with the axis of rotation, said wall having a plurality of confined radial discharge passages which are in the form of tubular conduits each closed around its full circumference, said radial passages providing the only communication between said labyrinth passage and said chamber, said radial passages having inlet ends which lie in a common circle around the circumference of said labyrinth passage, said radial passages being arranged in groups spaced around the circumference of said wall, the radial passages of each group diverging outwardly from their inlet ends at different angles from the axis of rotation with the outlet ends of different radial passages spread across the width of said chamber, and means for injecting liquid into the central portion of said spray head, thus enabling centrifugal force resulting from rotation of said spray head to throw the liquid through said labyrinth passage, which disperses the liquid into fine particles uniformly distributed circumferentially, and thence through said discharge passages, which distribute the particles across the width of said chamber, said chamber having openings in its outer circumference across the width thereof to discharge the particles tangentially in a broad pattern in the axial direction.

References Cited in the file of this patent UNITED STATES PATENTS 1,870,099 Croan Aug. 2, 1932 "2,515,665 Pieper July 18, 1950 2,850,322 Ingram Sept. 2, 1958 2,993,468 Zmuda et al July 25, 1961 FOREIGN PATENTS 302,980 Great Britain Dec. 24, 1928 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,061,200 October 30, 1962 Charles L. Ficker It is hereby certified that error appears in the above numbered patent requiring correctionend that th corrected below.

Column 4, lines 4 a an axis" and insert t column; line 13 nd 5, strike out "f0 he same after "means" strike out "confined",

r rotation about in line 6,- same Signed and sealed this 2nd day of April 1963.

(SEAL) Attest:

ESTON G. JOHNSON D V L. LADD Attesting Officer Commissioner of Patents 

